1. Field of the Invention
The present invention relates to a method of manufacturing a fin structure, and more particularly, to a method of manufacturing a fin transistor used in a semiconductor memory device.
2. Description of the Related Art
Fin transistors are suitable for design rule of 100 nm or less. In particular, fin transistors have been researched as low-powered, high-efficient, and high-speed devices. Active regions having extremely line widths of 20 nm or less are required to obtain full depletions of the fin transistors. In order to obtain fin transistors satisfying this requirement, it is very important to manufacture fin structures that are active regions.
Conventionally, a sidewall technique, ultraviolet lithography, electron beam lithography, etc. are sued to form fin structures. There is known a method of forming a polycrystal silicon fin structure on a silicon substrate using the sidewall technique. U.S. Patent Application Publication No. 2005-0048727 discloses a method of manufacturing a fin transistor using a sidewall crystal growth. In these conventional methods, with a narrow line width, uniformity of a fin structure is lowered, and it is costly to manufacture the fin structure.